Chlorination and ozonation of waste‐water: comparative analysis of efficacy through the effect onEscherichia colimembranes

Abstract

I . A RA N A, P. S AN TO R UM , A . MU EL A AN D I . BA RC I NA . 1999. The effect of chlorine and ozone on Escherichia coli cells resuspended in waste-water was compared. Selected chlorination and ozonation conditions produced a similar decrease in culturability (2-2·5 log). Under these conditions, differences in membrane permeability and cell surface hydrophobicity, depending on the disinfectant tested, were detected. After ozonation, while no changes in cell surface hydrophobicity were observed, approximately 95·5% of cells showed altered membrane permeability. The effect of chlorine was not linked to changes in membrane permeability. After chlorination, E. coli cells showed a tendancy to aggregate. The possibility that aggregation of cells could interfere with conventional colony counts is discussed. The degree of toxicity (Microtox TM assay) was unrelated to the effect on cellular activity.

Toxicity of Residual Chlorines from Hypochlorite-treated Seawater to Marine Amphipod Hyale barbicornis and Estuarine Fish Oryzias javanicus

“…Fortunately, ballast waters are kept at longer durations while the ships are in transit, so applying higher concentrations is not necessary. Effective disinfection can also be achieved by chlorination at lower concentrations as proven by a decrease of 2-2.5 log in culturability of Escherichia coli in wastewater after chlorination at 1-2 mg L −1 (Arana et al 1999) and the observed decimal reduction time of E. coli in seawater was ≤3 min using 0.5 mg L −1 NaOCl (Azanza et al 2001). Moreover, low-level chlorination (0.5-1.5 mg L −1 ) is actually being applied in cooling waters of coastal power stations against biofouling and was found out to produce very low concentrations of total residual oxidants (Jenner et al 1997).…”

Destruction of <i>Escherichia coli</i> and Broad-Host-Range Plasmid DNA in Treated Wastewater by Dissolved Ozone Disinfection under Laboratory and Field Conditions

“…They noted that ratios of viable-to-culturable E. coli can vary drastically depending on the nutrient status of wastewater treatment plant effluents. Additionally, Arana et al [32] noted that after chlorination, E. coli cells showed a tendency to aggregate, which could thereby affect the accuracy of conventional culture-based methods. A similar tendency for culture-based methods to enumerate Enterococci yielded lower values compared to qPCR methods [33].…”

Toxicological evaluation of the chemical oxidation methods for landfill stabilization

“…The possible mechanisms of the toxicities to the microorganisms used here can be explained by the effects on cell respiration, electron transport systems, ATP generation, rate of protein or lipid synthesis, cellular membrane function, and so forth (Battelle, 2003b). Arana et al (1999) found that damage to the membrane structure of the E. coil by oxidation processes led to an increase in permeability, ozone input, and cellular component oxidation. From the DaphTox test results with the A landfill leachate from 11/8/05 to 12/27/05, all the LC50 values at 24 h and 48 h after the exposure to the samples were over 100% except for A and E on 11/ 15/06 (Table 2).…”